The present invention relates generally to water heaters, and more particularly relates to apparatus and methods for receiving and draining away water leaking from the internal storage tank portion of a water heater.
Electric water heaters used to supply hot water to a variety of plumbing fixtures, such as sinks, tubs, showers and dishwashers, typically include a vertically oriented cylindrical metal water heating and storage tank coaxially disposed within an outer cylindrical metal jacket having an open lower end, and a diameter somewhat larger than that of the storage tank. A suitably insulation material is positioned within the annulus between the jacket and the storage tank and circumscribes the tank.
To hold the insulation within the jacket annulus, a short metal end cap is telescoped over the open lower end of the jacket and secured thereto with several screws extended inwardly through the end cap sidewall and into a lower end portion of the jacket side wall. To form a necessary grounding interconnection between the metal jacket and the metal storage tank, a metal grounding screw is customarily threaded upwardly through a central opening in the bottom wall of the end cap and into a lower end portion of the storage tank.
An electric resistance heating element extended into the storage tank is operated, under the control of a thermostat, to heat water stored in the tank to a predetermined temperature for supply to the plumbing fixture(s) to which the water heater is connected. Water supplied under pressure from the storage tank is automatically replenished through a cold water fill line operatively connected to the tank.
Because the water heater is typically hidden from view in a storage closet or the like, a leak in the storage tank portion of the water heater usually goes undetected. Water leaking from the tank enters the interior jacket annulus and quickly leaks out of the bottom of the water heater through the unsealed interface between the bottom end of the jacket and the bottom end cap and/or through holes in the bottom wall of the end cap (such as the hole for the grounding screw). If appropriate preventive measures are not taken, this undetected storage tank leakage can extensively flood and damage the heater storage floor (and surrounding floor areas) before the leakage is discovered.
The longstanding conventional solution to this tank leakage problem has been to provide a separate cylindrical catch pan which is coaxially positioned against the bottom end cap of the water heater. For example, the catch pan is placed on the floor (or a support shelf, as the case may be), and the bottom end of the water heater is supported on the bottom wall of the catch pan. The diameter of the catch pan is somewhat larger than the diameter of the bottom jacket end cap. Accordingly, there is defined within the pan an annular water receiving volume which outwardly circumscribes a lower end portion of the water heater.
In the event of a storage tank leak, water leaking from the internal storage tank and flowing outwardly through the bottom end of the water heater does not come in contact with the storage room floor. Instead, it flows into the annular receiving volume of the pan and is drained therefrom, via a suitable drain line connected to the pan, to a nearby floor drain or other drainage plumbing. Accordingly, the tank leak may continue, until detected and fixed, without flooding the storage area floor and surrounding floor areas.
Despite the widespread acceptance of separate catch pan structures, they are subject to a variety of well known problems, limitations and disadvantages. For example, the use of an auxiliary catch pan positioned beneath the overall water heater structure requires that an additional water heater component be fabricated, and then later installed at the job site, thereby increasing both the total manufacturing and installation costs associated with the overall water heating system.
Additionally, the heretofore required use of the separate catch pan increases the horizontal "footprint" of the overall water heater assembly. This undesirably increases the total water heater storage space requirements and (when the separate catch pan is shipped with its associated water heater) the overall shipping volume associated with the water heater.
It can be readily seen from the foregoing that it would be desirable to provide improved apparatus and methods for receiving and draining away water leaking from the internal storage tank portion of a water heater. It is accordingly an object of the present invention to provide such improved apparatus and methods.